–
q Control of message overhead for flooding is difficult:
q Unknown network coverage as a function of the distance d
q Coverage may rise e.g. from 3% to 30% in
one step d ® d + 1
q
q A random walk of predefined length L has fixed expense
q Randoms walks can proceed in parallel, with forking or
q can be enhanced by flooding with small d
from some points
q ̃ Many ways to combine random walks & flooding schemes
q (see
Gkantsidis et al., IEEE Infocom 2004 & ’05)
q Network
coverage is partial, but random walk searches are
q efficient
e.g. for replicated data in P2P networks
q Random
network growth is also efficiently supported by r. walks